And henry vollbrecht



UNITED STATES PATENT LUDwIe RIssMULLER, or NEWARK, NEW JERSEY, AND HENRY VOLLBRECHT, on NEW YORK, N. Y., ASSIGNORS TO THE NEWARK CHEMICAL woRKs, or NEWARK, N W JERsEY.

MANUFACTURE OF SUPERPHOSPHATES.

SPECIFICATION forming part of Letters Patent No. 494,940, dated April 4, 1893. Application filed $eptember 24, 1891. $erial No. &O6,7OZ. (N specimens.)

To all whom it may concern: quantity of mineral phosphate, such as phos- Be it known that we, LUDWIG RIssMiiLLER, phate of lime or other phosphate which does of Newark, New Jersey, and HENRY VOLL- not contain phosphoric acid in soluble form. BREGH'I, of the city and State of New York, In carrying this process into elfect, certain 5 have invented certain Improvements in the conditions are to be established, and certain Treatment of Animal Carcasses, Offal, and diificulties to be avoided. It is to be re- Bones for the Separate Collection of the Fat marked that the effectiveness of the concenand the Manufacture of Nitrogenous Supertrated sulphuric acid as a solvent of the orphosphates Therefrom, of which the following ganic substances present in the raw material IQ is a specification. depends somewhat upon the scale of the op- There have heretofore been practiced two oration, and that it is most effective when cmmethods of treating bones and other animal ployed in a large volume upon a large quanmattersfor the extraction of the fat and manutit-y of raw material. There is then manifacture of fertilizers therefrom. In one fesied what may be called mass action, as the 15 method they are rendered by treatment in result of which the organic substances are boiling water. In addition to the sanitary rapidly dissolved. The quantity'of acid cmobjections to this mode of treatment, it is to ployed will vary according to the amount of be remarked that certain portions of the fat moisture present in the raw material. WVhen are so inclosed, especially in the bones, that the raw material contains, say, not over fifty 20 they cannot be freed by boiling in water or per cent. of moisture, it will be sufficient to by evaporation, and hence such portions of submerge it in a bath of hot sulphuric acid the fat are lost. In the other methodreferred of 50 Baum. If the amount of moisture to, the raw material is treated in a closed vespresent in the raw material greatly exceeds sel with extracting agents, such as benzine or fifty per cent, a larger quantity of acid may 2 5 other hydrocarbons; but such extracting be required in order to prevent such excess of agents cannot be wholly recovered, and there moisture from too greatly reducing the denis hence a loss which materially enhances the sity of the acid and thereby diminishing its cost of the product. Bones treated by either effectiveness as a dissolving agent. On the of the methods referred to retain their nae other hand, if the raw material contains con- 3o ural structure, and are necessarily dried and siderably less than fifty per cent. of moisture,

ground in order to convert them into a bone as, for example, if it consists of butcher bones 8o meal, or superphosphate, but this involves a alone, a less quantity of acid maybe required,

sensible loss of nitrogen. or an acid of lower density, say 40 or 45 The objects of the present invention are to may be high enough for the required purpose. 3 5 obtain all the commercially valuable constitu- One of the serious difiiculties to be guarded ents present in the raw material without the against is the tendency of the fat and fat loss of any of the fat or any of the nitrogen, acids to form an emulsion with the gypsum and at the same time to render the phosphoric which is formed when the bones commence acid present soluble, and also to avoid the to dissolve. It is hence necessary that the 40 sanitary objections referred to. These obfats and fat acids shall be skimmed ofi as jects are attained by dissolving the organic fast as they rise to the surface of the treat- 0 substances present in the raw material in hot ing bath, and that there shall be no such mesulphuric acid of high density, and by conchanical disturbance of the raw material durtinuously skimming off and separately c0ling its treatment as would be caused by stir- 45 lecting the fat as fast as it rises to the surring, or by the injection of steam directly face during the formation of the solution, into it, or by cbullition. and by converting the solution, after the re- While it is desirable to maintain the raw moval of the fat, into nitrogenous superphosmaterial and the treating bath at a high temphate by the addition thereto of a suitable perature, care must therefore be taken notto allow the temperature to rise to the boiling point.

The treating operation is performed in a leaden vat which may be heated externally, and which may have arranged in it a heating coil of lead pipes.

In carrying the process into operation, the vat is partly filled with sulphuric acid of a suitably high density, and after the acid has been heated to a temperature of say, 200 Fahrenheit, the raw material is submerged in it, and the heat maintained until the temperature, reduced by the introduction of the raw material, has again been brought up to 200 Fahrenheit, care being taken not to raise the temperature so quickly as to cause foaming by the too rapid generation of carbonic acid from the carbonate of lime present in the raw material. The fat and the fat acids, skimmed ed the surface of the resultant s0- lntion as fast as they rise, are separately collected for commercial disposal. During the treatment the gypsum present is precipitated to the bottom of the vat in the form of a muddy sediment. The phosphoric acid and the nitrogen present are rendered soluble by the sulphuric acid. An excess of acid is preferably employed, and to convert the solution into a fertilizer there is added to it a sufficient quantity of raw phosphate of lime to take up the free sulphuric acid present-,which free acid also renders substantially all the phosphoric acid of the added phosphate soluble. The resulting product is a comparatively dry fertilizer in condition for use.

The sanitary advantages of the process are ob'vious:The germs originally present in the raw material are destroyed, and there is an entire absence of the stenches which make the ordinary processes of rendering so disagreeable. Owing to the destruction of the germs, the process may be carried on Without endangering the health of persons engaged in or residing near the disposal works.

What is claimed as the invention is The herein-described improvement in the treatment of animal carcasses, oifal and bones for the separate collection of the fat, and the manufacture of nitrogenous superphosphates therefrom, which consists in subjecting the raw material to the action of sulphuric acid of high density to a temperature of about 200 Fahrenheit until the nitrogenous substances present are dissolved, and in skimming off and separately collecting the fat and fat acids as fast as they are freed and rise to the surface, and in finally adding to the remaining solution sufficientraw phosphate to take up all the free sulphuric acid present, and thereby form in condition for use as a fertilizer a comparatively dry nitrogenous superphosphate, substantially all the phosphoric acid in which is soluble, and which contains also in soluble form all the nitrogen originally present in the raw material.

L. RISSMULLER. H. VOLLBRECHT. Witnesses:

M. L. ADAMS, A. M. JONES. 

